No abstract

Meteorological and water quality data were collected in offshore and nearshore settings over 4 years in the oligotrophic–mesotrophic Owasco and Seneca Lakes in order to assess cyanobacteria bloom (CyanoHABs) spatial and temporal variability and precursor meteorological and water quality conditions. CyanoHABs were detected from August through mid-October in both lakes. Blooms were temporally and spatially isolated, i.e., rarely concurrently detected at 3 (4.2%) or more of the 12 sites, and blooms (75.6%) were more frequently detected at only 1 of the 12 sites in the 10 min interval photologs. Both lakes lacked consistent meteorological and water quality precursor conditions. CyanoHABs were detected during the expected calm (<1 kph), sunny (600–900 W/m2), and warm water (>23 °C) episodes. However, more CyanoHABs were detected during overcast/shady (<250 W/m2) and windier (1 to 20 kph) and/or in cooler water (16 to 21 °C). More importantly, the majority of the sunny, calm, and/or warm water episodes did not experience a bloom. This suggests that nutrient availability was essential to trigger blooms in these two lakes, and we speculate that the nutrients originate from the decomposition of nearshore organic matter and runoff from the largest precipitation events.